var ipt=document.getElementById('sousuo');
ipt.onfocus=function(){
	if(this.value=='纪念品'){
			this.value='';
	    	this.style.color='#000';
	}
}
ipt.onblur=function(){//onblur事件会在对象失去焦点时发生
	if(this.value==''){
		this.value='纪念品';
		this.style.color='#888';
	}
}
